This invention relates to liquid displacement pumps and the like and, in particular, to means for controlling the delivery rate thereof.
When pumping liquids in certain fields, the flow rate thereof can be critical. Illustrative of such fields are the pumping of physiological liquids in the medical field and the pumping of liquids in liquid chromotography systems. In the medical field, infusion pumps are employed where the liquid is precisely metered into a patient's circulatory system. It is typical in these systems to set a predetermined flow rate at which fluid is delivered, it being assumed that the fluid will indeed be delivered at the desired rate. However, if gas is present in the pump, the flow rate will typically be less than that required.